The man jailed for the murder of a Christchurch prostitute has had his murder conviction quashed.

Mauha Fawcett was found guilty in the High Court at Christchurch of Mellory Manning's murder and jailed in 2014.

But his family confirmed to the Herald that the Crown has ruled that he was wrongfully convicted. The decision was made at the Court of Appeal in Wellington today.

The Court of Appeal allowed the appeal, quashed the conviction and ordered a retrial. Fawcett was remanded in custody until September 1 in the Christchurch High Court.

The reasons are suppressed until final disposition at trial (in accordance with the usual pre-trial approach).

Manning's brother Rob was not surprised by the decision to quash Fawcett's conviction.

"We know that there are obviously other people responsible for it," he told the Herald.

"Even though [Fawcett] got convicted of the crime, it was only one part of it and I was actually wondering what was happening with the rest of [the police investigation], I hadn't heard anything [over the past 3 years].

"The police still need to be looking for the other people involved in it."

Rob Manning said the appeal "brings it all back again" and he and his family are still far from getting closure.

Manning was abducted by Mongrel Mob members, raped and murdered in December, 2008.

It stemmed from a drug debt.

Her body was found the next morning in the Avon River.

Fawcett was apparently trying to get into the gang at the time. The Crown said he was highly unlikely to have been the main perpetrator during the attack, but had played "a pivotal role in the operation".

Manning's death was the third prostitute murder in the city in as many years and its brutality shocked senior, experienced investigators.

Fearing the gang would dob him in to police or else take him out over fears he would talk to police, Fawcett fled the city.

Over a series of police interviews, he incriminated himself in the killing, but later back-tracked, according to a Herald court report at the time.

The Crown alleged he also made a confession to a former Mongrel Mob member, saying he had stabbed Manning once.

During the trial he conducted his own defence, with assistance by an amicus curiae, and said he had lied throughout the interviews. He also claimed police had pressured and "coached" him into making false confessions.

Fawcett, who has a British bulldog tattooed on his face, said he hadn't been at the gang pad that night and denied having anything to do with her murder but the jury rejected his version of events.